<!doctype html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="myCanvas" width="300" height="200"></canvas>
<script type="text/javascript">
var ctx = document.getElementById('myCanvas').getContext('2d');
var lineJoin = ['round','bevel','miter'];
ctx.strokeStyle = 'blue';
for (var i=0;i<lineJoin.length;i++){
	ctx.lineWidth = 25;  
	ctx.lineJoin = lineJoin[i];
	ctx.beginPath();
	ctx.moveTo(10+i*150,30);
	ctx.lineTo(100+i*150,30); 
	ctx.lineTo(100+i*150,100); 
	ctx.stroke();
}


</script>
</body>
</html>  
